Kimberly-Clark Professional conducted a study to identify the workplace hotspots where germs can lurk. Hygienists from the company collected nearly 5,000 individual swabs from office buildings housing more than 3,000 employees. According to the study, surfaces tested and found to have high levels of contamination included break room sink tap handles, microwave door handles, keyboards, refrigerator door handles, water cooler buttons and vending machine buttons. Half of all computer mice and desk phones were found to have ATP levels above 100.